Articles

Slow mass movement of the soil is a form of transporting of slope material. It can be classified according to: the dynamics of the process, the structure of the movement (particles, layers) and the relation to the morphological surface (shallow or deep movement). In this way it is possible to distinguish soil creep as the important process within this group of mass wasting factors. Seasonal creep is first of all a function of climate whereas continuous or rheological creep is a function of geological structure.The slow movement of the soil depends on local factors (slope angle, moisture of the soil, vegetation cover) and on latitudinal and altitudinal climatic zonal factors (temperature, precipitation). The rate of soil movement in the polar (periglacial) zone is the highest on the globe. It is, as mass movement of the soil, three times higher than in the alpine zone. The soil creep processes in temperate climates are relatively small but greater than in the tropic zone. The smallest soil movement is in the arid and semi-arid zone.

The vertical alteration of geomorphic systems results from Quaternary evolution. The huge stabilized landslides are the main feature of the slope morphology. They were produced in a periglacial zone of the older Rio Blanco glaciation. The present glacial and cryonival systems were affected by the Punrun glaciation phase and postglacial climatic conditions. The valley bottoms and the lowermost parts of the slopes were transformed by mass movements and mud/debris flows in the postglacial period.

Results of field investigations at the northern foot of East Kunlun Mts. as well as the known so far literature data allowed a reconstruction to be made of the history and type of glaciation and déglaciation of this area during the Late Pleistocene and Early Holocene. The former glaciers had developed as piedmont glaciers debouching into the high-glacial Qaidam Lake. The largest glaciers at their maximum stage reached about 45 km in length and at least 20 km in width, producing great quantities of glacial and glaciofluvial material which have been fixed in thick sequences within the area of the former Qaidam Lake. At the decline of the Pleistocene, the piedmont glaciers underwent a large-scale stagnation probably brought about by a rapid decrease in moist air flux. In consequence, kame terraces abutting on the mountain ridges were formed. They are interstratified and covered with angular debris of supraglacial derivation, protecting them against post-depositional erosion and denudation. The latter feature contributed to the fact, that the kame terraces have remained in almost unshaped form up to the present. The thermoluminescence dating of kame sediments yielded a date which suggests that local déglaciation of the investigated foot of the East Kunlun Mts. took place early in the Holocene, around 8000 years BP.

The present study is (1) an attempt to outline the reasons for and the course of the ageing transition in Austria, and (2) to predict what might be the social consequences of this process.It seems clear that the social outcomes of demographic ageing and increased longevity discussed in this paper represent only a very selective view of societal consequences for the demographic development of the coming decades. The entire complex raises essential questions about one's place in society and meaning of life in the some twenty years between, first, ceasing gainful employment and finally, death (Imhof 1981; Neugarten and Neugarten 1986; Gockenjan and Kondratowitz 1988; Ehmer 1990). Both society as a whole and the individual will be faced with the necessity to answer these questions. Together with other academic disciplines, demography and population geography can share the attempt to answer these questions.

Climatic amelioration in the Holocene resulted in a rise of the upper timberline in the Balkan Mts. (Stara Planina) up to 1800-1950 m a.s.l. Incorporation of the Balkan Peninsula in the Turkish Empire in the 14/15 centuries has opened the Muslim markets for mutton, skin and wool. As a result of grazing pressure, the upper timberline has been lowered by several hundred metres over the last 4-5 centuries. This exposed Pleistocene slope deposits to contemporary geomorphic processes. The results of these processes occur over the entire area above the timberline, but are in particular well developed between 1500-1700 m a.s.l. on slopes which were formerly afforested.In these areas small slumps or landslides are very common on fine grained slope deposits. On the debris-loamy slope deposits semi-circular niches, 5-8 m long, are common. As a result of upslope enlarging and capturing of adjacent niches, the grass ridges separating them become isolated "monadnocks". In the areas underlain by shales, on slopes with gradients exceeding 30°, soil slides are particularly common.Processes of slope degradation caused by the overgrazing exhibit various stages of development. Some areas are characterized by fresh relief forms, other by more subdued forms which are progressively colonized by vegetation.

On the basis of the 12 years of field studies (1975-1987) regularities in the dynamics of high mountain fluvial system in an annual cycle have been determined. The results have been compared with the results obtained for other high mountain regions of the temperate zone.

The article is a review of Polish pedological studies carried out on Spitsbergen since 1957. The first part deals with the important papers going through the sections of soil science. Special attention was focused on arctic soil forming processes, physical properties (changes in soil volume, soil movements, thermal features), chemical properties and soil biology. Another part gives the lines for future pedological studies.

Contrary to widely held opinions, the archipelago of the Svalbard Islands does not belong to the oceanic part of the periglacial zone but has its own diversified climate being humid-maritime on the coast and dry-continental in the interior. These differences in the periglacial enviroments manifest themselves in contrasting structures of the active layer. The periglacial zone of the last glaciation in Europe was characterized by a climatic gradient more oceanic in the west and more continental in the east of Europe. The transitional section of this zone lay in its narrowest part, between the Scandinavian ice border and the northern timber line, delimited approximately by the arch of the Alps and Carpathian Mountains. In this part periglacial structures are abundant and, what is more variable in vertical profile.This evidence reflects great variations in the glaciation period, of changes of the oceanic and continental phases. There are at least 4 frost wedge horizons, often of "sand wedge" type, that are indicators of a continental climate. The Svalbard archipelago where oceanic as well as continental facies of periglacial structures can be found at present provides a good representation of the spatial diversity of periglacial phenomena which occurred at different times in Central Europe.

Detrital cohesive deposits belong to the most common present-day sediments known from various terrestrial environments, some shallow-marine ones as well as tidal flats. Lithologically, they include a very wide range of clastic materials varying in size from rudites (angular or rounded), through arenites, to lutaceous materials. Detrital cohesive deposits constitute a variety of landforms from small anthills to extensive floodplain sheets or prominent clay dunes that accompany some coastal zones. To the most common lithologie variétés belong clay rubble, clay gravel (pebbles, balls), soil pebbles (sand) clay sand (clayarenite) soil sand (soilarenite) and soil mud (soillutite). Genetically, the deposits may be classified as autoclastic, hydroclastic, anemoclastic, bioclastic or hybrid. All transitions may be encountered from pure cohesive deposits, through mixed ones, to ordinary (epi)clastic materials. Mixed deposits (e.g. the majority of intraformational conglomerates) have perhaps the best chance to be preserved in a fossil record and have been reported since the Late Pre-Cambrian till the Holocene.

Inselbergs are the most striking feature of the granite scenery of the Jelenia Góra Basin. They are either lithologically or fracture controlled. The former are built up of more resistant types of the granite (aplogranite, equigranular granite), while the latter reflect mostly the occurrence of domical structures. Therefore they could be considered as bornhardts. The properties of granite, which forms bornhardts indicate, that the selective deep weathering of Tertiary age following or accompanying by stripping was the most important morphogenetic process leading to the origin and exposure of the residual hills. After the exposure bornhardts were developed in changing morphoclimatic conditions. The formerly steep-sided, bare slopes were remodelled to the form of the boulder-controlled slopes due to strong physical disintegration of domes in the dry environments. The age of this process is probably Late Miocene. Both Pliocene and Pleistocene morphogenesis, which took place respectively in temperate and cold conditions, did not change the inselberg landscape considerably.

The cuesta landscape has been analysed in the border area of the Upper Bóbr River drainage basin and the Upper Ścinawka Kłodzka River drainage basin. Thanks to differentiations within the monoclinal basement of the area, it was possible to observe the structural control of relief forms and influence of the structure on the evolution of those forms. On the other hand, the localization of the study area in the border zone of two different drainage basins makes it possible to analyse the influence of the intensity of river erosion on the shapes and morphodynamic of escarpment forms in both drainage basins of the same rocks. Cuestas, a valley step and resistance scarps have been found within the study area. Evidence of the lively morphodynamic of those forms in the Pleistocene is dealt with.

The Dnieper river valley, in spite of being and old one, has only young terraces preserved in the section between Orsha and Shklov: tow Vistulian-Young Pleniglacial terraces and two levels of the Late Glacial-Holocene flood plains. With a large horizontal stability of the channel, the modelling of flood plains resulted only form a vertical accretion of flood sediments. Phases of the intensified activity of the Dnieper which have been identified on the border of the Atlantic and Subboreal and during the Subatlantic about 1000 years BP manifested themselves here by changes of the type of sedimentation on flood plains. These phases are conditioned by the climate, although in the younger one a remarkable influence of human activity is evident.

The paper deals with a proposal of constructing a model of formation of the specific Carpathian variety of loesses during the Vistulian. It is based on the observation and measurements of the actual activity of winds, the occurrence of blowouts containing lacustrine-boggy deposits of Allerod-Holocene age, as well as on the occurrence of ventifacts and covers of radiocarbon dated Plenivistulian anemoclastic silty-clayey sediments, a dozen or so metres thick.

The purpose of the present study was the answer to the question whether sedimentological features of dune deposits make a record of the duration of desertification processes. According to the author, the features of dune sediments showing the duration of aeolian processes, indirectly indicate the period of lasting of desert conditions. Particularly informative of the duration of aeolian processes is the degree of transformation of dune sediments in relation to source sediments as for their grain size distribution, mineral composition, as well as the features of abrasion and frosting of quartz grains (with the use of electron microscope analysis as one of the research methods).

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Elżbieta Mycielska-Dowgiałło, Laboratory of Sedimentology, Faculty of Geography and Regional Studies, University of Warsaw, Warsaw, Poland

The results of geomorphological and hydrological investigations, carried out in the Western Cuba, have been presented. The investigations were carried out in the catchment basin Cuyaguateje located in the Sierra de los Organos and two small subterranean catchment basins in the massif Pan de Guajaibon in the Sierra del Rosario. The differences between ways of water circulation in a well developed upland karst region (Cuyaguateje) and in a well isolated limestone massif (Pan de Guajaibon) have been shown. The former is dominated by an underground transit water flow through mogot type hills, the latter is dominated by a local circulation of waters in the subterranean basin discharged by a central conduit. According to several years of investigations, elements of the hydrological balance, changes in chemical composition have been determined and values of chemical denudation have been calculated. Large amounts of underground waters have been emphasized. They result from the intensity of the rainfall, and from fast retention of rain waters in a karst massif. It causes an intensive process of chemical denudation, which reaches in mean perennial values, 90 m3/ km2/Y. Such results are representative for tropical karst and they have been compared with chemical denudation values in karst regions in other climatic zones.